Micrographia, by Robert Hooke

Observ. iv. Of fine waled Silk, or Taffety.

This is the appearance of a piece of very fine Taffety-riband in the bigger magnifying Glass, which you see exhibits it Schem. 3.Fig. 1. like a very convenient substance to make Bed-matts, or Door-matts of, or to serve for Beehives, Corn-scuttles, Chairs, or Corn-tubs, it being not unlike that kind of work, wherewith in many parts in England, they make such Utensils of Straw, a little wreathed, and bound together with thongs of Brambles. For in this Contexture, each little filament, fiber, or clew of the Silk-worm, seem'd about the bigness of an ordinary Straw, as appears by the little irregular pieces, ab, cd, and ef; The Warp, or the thread that ran crossing the Riband, appear'd like a single Rope of an Inch Diameter; but the Woof, or the thread that ran the length of the Riband, appear'd not half so big. Each Inch of six-peny-broad Riband appearing no less then a piece of Matting Inch and half thick, and twelve foot square, a few yards of this, would be enough to floor the long Gallery of the Loure at Paris. But to return to our piece of Riband: It affords us a not unpleasant object, appearing like a bundle, or wreath, of very clear and transparent Cylinders, if the Silk be white, and curiously ting'd; if it be colour'd, each of those small horney Cylinders affording in some place or other of them, as vivid a reflection, as if it had been sent from a Cylinder of Glass or Horn. In-so-much, that the reflexions of Red, appear'd as if coming from so many Granates, or Rubies. The loveliness of the colours of Silks above those of hairy Stuffs, or Linnen, consisting, as I else-where intimate, chiefly in the transparency, and vivid reflections from the Concave, or inner surface of the transparent Cylinder, as are also the colours of Precious Stones; for most of the reflections from each of these Cylinders, come from the Concave surface of the air, which is as 'twere the foil that incompasses the Cylinder. The colours with which each of these Cylinders are ting'd, seem partly to be superficial, and sticking to the out-sides of them; and partly, to be imbib'd, or sunck into the substance of them: for Silk, seeming to be little else then a dried thread of Glew, may be suppos'd to be very easily relaxt, and softened, by being steeped in warm, nay in cold, if penetrant, juyces or liquors. And thereby those tinctures, though they tinge perhaps but a small part of the substance, yet being so highly impregnated with the colour, as to be almost black with it, may leave an impression strong enough to exhibite the desir'd colour. A pretty kinde of artificial Stuff I have seen, looking almost like transparent Parchment, Horn, or Ising-glass, and perhaps some such thing it may be made of, which being transparent, and of a glutinous nature, and easily mollified by keeping in water, as I found upon trial, had imbib'd, and did remain ting'd with a great variety of very vivid colours, and to the naked eye, it look'd very like the substance of the Silk. And I have often thought, that probably there might be a way found out, to make an artificial glutinous composition, much resembling, if not full as good, nay better, then that Excrement, or whatever other substance it be out of which, the Silk-worm wire-draws his clew. If such a composition were found, it were certainly an easie matter to find very quick ways of drawing it out into small wires for use. I need not mention the use of such an Invention, nor the benefit that is likely to accrue to the finder, they being sufficiently obvious. This hint therefore, may, I hope, give some Ingenious inquisitive Person an occasion of making some trials, which if successfull, I have my aim, and I suppose he will have no occasion to be displeas'd.